Opening a Terminal to the extracted directory, I then compiled the code:

PowerShell

1

2

3

$cdicu/source

$./runConfigureICU MacOSX

$make&&sudo make install

As I did not have autoconf, I installed it using Brew. Alternatively, you can compile it from source if you do not have Brew.

PowerShell

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$brew install autoconf

The next few steps are where I had some problems. I was getting strange errors:

fatal error: 'php.h' file not found
and"ERROR: `phpize' failed"

Digging around, it turns out there’s a bit of a strange bug here. It can be quite simply solved by downloading/updating XCode from the App Store and symlinking the XCode SDK headers to the MAMP directory: